To prevent an application from consuming too much system resources, the Apple Engineer Gate that developed iOS designed a "watchdog" mechanism. In different scenarios, the watchdog monitors the performance of the application. If the runtime is exceeded by the scenario, the watchdog will force the end of the application process. In Crashlog, developers will see error codes such as 0x8badf00d.
This is particularly true in the case of arc and the low phone model.
The exception code 0x8badf00d indicates that's application has been terminated by IOS because a watchdog timeout . The application took too long to launch, terminate, or respond to system events. One common cause of this is doing synchronous networking on the main thread. Whatever operation is in thread 0:needs to being moved to a background thread, or processed differently Block the main thread.
Apple doc address; https://developer.apple.com/library/ios/technotes/tn2151/_index.html